test for callbacks from write_gen4_lat (adaptor for GENESIS 1.3, v4)

[ZeugAusHH]

Description:

• Implements tests for callback functionality recently added to write_gen4_lat function in adaptor for GENESIS 1.3, v4.
• Disabled broken test function test_beam_transform in adaptor for GENESIS 1.3, v2 (file ocelot/adaptors/genesis.py).

Note that currently the test triggers about 30 warnings of type PendingDeprecationWarning resulting from use of the deprecated numpy.matrix in the genesis.py. To fix these, changes to genesis.py will be needed.